UNIT 3 - KA4 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What does the nervous system consist of

A

The nervous system consist of a complex network of nerve cells called neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of neurons

A

Neurons receive and transmit electrical impulses (nerve impulses) and provide the body with a rapid means of communication and control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three types of neuron

A
  1. Sensory
  2. Inter
  3. Motor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does sim do

A

Sim does crazy actions

A nerve impulse always travels:

Dentrites ———> cell body ———> axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Draw and label sensory neuron from left to right

A

Dentrites - axon - cell body - myelin sheath - axon terminals

direction of nerve impulse ———>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a difference in the structure of sensory neuron to other neurons

A

The cell body sits part way along the axon and there are no Dentrites on the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Draw and label inter neuron from left to right

A

Dendrites - cell body - axon - axon terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference in the structure of inter neurons to other neurons

A

The axon is very short and lacks myelination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Draw and label motor neuron from left to right

A

Dendrites - cell body - axon- myelin sheath - motor end

——— > direction of nerve impulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dendrite

A

Receive nerve impulse and pass them towards a cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cell body

A

The control centre of the cells metabolism and contains clusters of ribosomes. And contains the nucleus and most of the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Axon

A

An axon is a single nerve fibre that carries nerve impulses away from a cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Myelin

A

Axons are surrounded by a myelin sheath which insulates the axon and increases the speed of impulse conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When is myelination completed

A

Myelination is not completed at birth, but continues from birth until adolescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to the response to stimuli in the first two years as a result of myelination

A

Responses to stimuli in the first two years of life are not as rapid or co-ordinated as those of an older child or adult

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What can certain diseases do to myelin sheath

A

Certain diseases destroy the myelin sheath causing a loss of coordination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of glial cells

A

Glial cells produce the myelin sheath and support neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where do neurons connect

A

Neurons connect with other neurons or muscle fibres at a synaptic cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the neurons before and after the synapse called

A

The neurone before the synapse is called the presynaptic neuron and the neuron after the synapse is called the post synaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where are neuron transmitters stored (1st stage of transmission at a synapse)

A
  1. Neurotransmitters are stored in the vesicles in the axon endings of the presynaptic neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where are the neurotransmitters released (2nd stage of transmission at a synapse)

A

They (the neurotransmitters) are released into the (synaptic) cleft on arrival of an impulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where do they diffuse (3rd stage of transmission at a synapse)

A
  1. They (the neurotransmitters) diffuse across the cleft
23
Q

What do neurotransmitters bind to (4th stage of transmission at a synapse)

A
  1. They (neurotransmitters)bind to receptors on the membrane of the postsynaptic neuron
24
Q

Draw and label diagram of the synapse

A

Check jotter

25
Q

Transmission at a synapse summary

A

Neurotransmitters are stored in vesicles in the axon endings of the presynaptic neuron. They are released into the cleft on arrival of an impulse. They diffuse across the cleft and bind to receptors on the membrane of the postsynaptic neuron

26
Q

Where do neurotransmitters relay impulses

A

Neurotransmitters relay impulses across the synaptic cleft

27
Q

What should happen to neurotransmitters as soon as the impulse is transmitted

A

Neurotransmitters must be rapidly removed by enzymes or reuptake as soon as the impulse is transmitted to prevent continuous stimulation of postsynaptic neurons

28
Q

What can nerve impulses be

A

Nerve impulses can be excitatory or inhibitory

29
Q

Excitatory

A

Excitatory signals increase the chance of impulse being transmitted

30
Q

Inhibitory

A

Inhibitory signals decrease the chance of the impulse being transmitted

31
Q

What determines whether the signal is excitatory or inhibitory

A

Receptors determine whether the signal is excitatory or inhibitory not the neurotransmitter

32
Q

How is the threshold reached on the post synaptic membrane to transmit an

A

A minimum number of neurotransmitter molecules must attach to the receptors in order to reach the threshold on the postsynaptic membrane to transmit the impulse

33
Q

What can synapses filter out

A

Synapses can filter out weak stimuli arising from insufficient secretion of neurotransmitter.

34
Q

What series is enough to trigger an impulse

A

Summation of a series of weak stimuli can release enough neurotransmitter to trigger an impulse

35
Q

Which type of neural pathway can release enough neurotransmitter to reach the threshold

A

Convergent Neural pathways can release enough neurotransmitter molecules to reach the threshold and trigger an impulse

36
Q

What is the function of endorphins

A

Endorphins are neurotransmitters that stimulate neurons involved in reducing the intensity of pain

37
Q

What does the production of endorphins increase in response to

A

Endorphin production increases in response to severe injury, prolonged and continuous exercise, stress and certain foods

38
Q

Which feelings are increased levels of endorphins linked to

A

Increased levels of endorphins are also linked to the feelings of pleasure obtained from activities such as sex, eating and prolonged exercise

39
Q

What is the function of dopamine

A

Dopamine Is a neurotransmitter that induces feelings of pleasure and reinforces particular behaviour by activating the reward pathway in the brain

40
Q

Which neurons does the reward pathway involve

A

The reward pathway involves neurons which secrete or respond to dopamine

41
Q

When is the reward pathway activated

A

The reward pathway is activated when an individual engages in a behaviour that is beneficial to them eg. Eating when hungry

42
Q

What are many drugs used to treat neurotransmitter related disorders

A

Many drugs used to treat neurotransmitter related disorders are agonists or antagonists

43
Q

What are agonists

A

Agonists are chemicals that bind to and stimulate specific receptors mimicking the action of a neurotransmitter at a synapse

44
Q

What are antagonists

A

Antagonists are chemicals that bind to specific receptors blocking the action of a neurotransmitter at a synapse

45
Q

How do other drugs act

A

Other drugs act by inhibiting the enzymes that degrade neurotransmitters or by inhibiting uptake of the neurotransmitter at the synapse causing an enhanced effect

46
Q

What can recreational drugs act as

A

Recreational drugs can also act as agonists or antagonists

47
Q

How do recreational drugs affect neurotransmission

A

Recreational drugs affect neurotransmission at synapses in the brain altering an individuals mood, cognition, perception and behaviour

48
Q

Which pathway can recreational drugs affect

A

Many recreational drugs affect neurotransmission in the reward pathway of the brain

49
Q

What is drug addiction caused by

A

Drug addiction is caused by repeated use of drugs that act as antagonists

50
Q

What is drug tolerance caused by

A

Drug tolerance is caused by repeated use of drugs that act as agonists

51
Q

How do antagonists affect the nervous system

A

Antagonists block specific receptors causing the nervous system to increase both the number and sensitivity of these receptors

52
Q

Which sensation leads to addiction

A

Antagonists block specific receptors causing the nervous system to increase both the number and sensitivity of these receptors. This sensation leads to addiction where the individual craves more of the drug

53
Q

How do agonists affect the nervous system

A

Agonists stimulate specific receptors causing the nervous system to decrease both the number and sensitivity to these receptors

54
Q

Which desensitation leads to drug tolerance

A

Agonists stimulate specific receptors causing the nervous system to decrease both the number and sensitivity of these receptors. This desensitisation leads to drug tolerance where the individual must take more of the drug to get an effect